He would offer families a $5,000 tax credit to help buy insurance policies.
"Millions of Americans would be making their own health care choices again," McCain said in remarks prepared for delivery Tuesday at the H. Lee Moffitt Cancer Center & Research Institute in Tampa.
"Insurance companies could no longer take your business for granted, offering narrow plans with escalating costs," he said. "It would help change the whole dynamic of the current system, putting individuals and families back in charge, and forcing companies to respond with better service at lower cost."
His campaign called the speech a major policy address, though McCain has talked about the same ideas for several months. What's new, according to adviser Doug Holtz-Eakin, is that McCain will give more examples of how his policies would work.
Still missing: The total cost of the plan and an estimate of how many people it would help. There are more than 40 million people in the United States who don't have health insurance.
"So, a little more detail, but remember, it is April, and the election's in November, so not everything will happen tomorrow or this week," Holtz-Eakin told reporters Monday.
Under McCain's plan, anyone could get the credit, and those who like their company health care plan could choose to stay in it. The credit would be available as a rebate to people at lower income levels who have no tax liability, Holtz-Eakin said.
To pay for the tax credit, McCain would eliminate the tax exemption for people whose employers pay a portion of their coverage, raising an estimated $3.6 trillion in revenues, Holtz-Eakin said. Companies that provide coverage to workers still would get tax breaks. McCain would also cut costs by limiting health care lawsuits.
The goal is to move the health care industry away from job-based coverage toward competition among health insurance companies on the open market.
Candidates' Health Care Proposals
WebMD Details The Health Care Proposals Of The Presidential Candidates
"No one should believe that John McCain is of the opinion that the current individual market is a great place to go shopping for insurance; it's not," Holtz-Eakin said.
Critics of McCain's approach say it could leave sicker or older people without coverage; McCain's campaign says there would be a safety net to protect high-risk people.
Some Democrats weren't buying it. McCain drew criticism Monday from Elizabeth Edwards, wife of former Democratic presidential hopeful John Edwards.
"John McCain's health care program works very well, if you happen to be rich and healthy," said Edwards, now a senior fellow at the Center for American Progress Action Fund, a Democratic-leaning group.
McCain also would let people buy health insurance across state lines instead of limiting them to companies in their own states. He said companies that do business in multiple states have greatly reduced health care costs because they are able to offer policies in many states.
Democrats worry about this idea because it could exempt insurers from stricter state regulations, such as requiring coverage of mammograms.
McCain issued his own criticism of Democratic plans for health care, saying and want government-run health care because they seek mandatory health care coverage, Obama for children and Clinton for everyone.
"They want government to make the decision," McCain, who opposes mandates, said Monday at Miami Children's Hospital. "I want the family to make the decision as to what kind of health care they want for their children."